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  • Open access
  • 54 Reads
Characterization of Atmospheric Reactive Nitrogen Emissions from Global Agricultural Soils

Global nitric oxide (NO) emissions into the atmosphere are projected to increase in the coming years with the increased use of synthetic nitrogen fertilizers and fossil fuel combustion. Here; a statistical model (NO_STAT) is developed for characterizing atmospheric NO emissions from agricultural soil sources; and compared to the performance of other global and regional NO models (e.g., EDGAR and U.S. EPA). The statistical model was developed by developing a multiple linear regression between NO emission and the physicochemical variables. The model was evaluated for 2012 NO emissions. The results indicate that, in comparison to other data sets; the model provides a lower global NO estimate by 59%, (NO_STAT: 0.67 Tg N yr-1; EDGAR: 1.62 Tg N yr-1). We also performed a region-based analysis (U.S., India; and China) using the NO_STAT model. For the U.S., our model produces an estimate that is 47% lower in comparison to EDGAR. Meanwhile; the NO_STAT model estimate for India shows NO emissions 75% lower when compared to other data sets. A lower estimate is also seen for China; where the model estimates NO emissions 82% lower than other data sets. The difference in the global estimates is attributed to the lower estimates in major agricultural countries like China and India. The statistical model captures the spatial distribution of global NO emissions by utilizing a more simplified approach than those used previously. Moreover; the NO_STAT model provides an opportunity to predict future NO emissions in a changing world.

  • Open access
  • 87 Reads
Analysis of the Particulate Matter Pollution in the Urban Areas of Croatia, EU

Particulate matter (PM) comprises a mixture of chemical compounds and water particles found in air. The size of suspended particles is directly related to the negative impact on human health and the environment. Children are particularly sensitive to the effects of air pollution because they breathe faster than adults and thus absorb more pollution. In this paper we presented an analysis of the particulate matter pollution in urban areas of the Republic of Croatia, EU. Data on PM10 and PM2.5 concentrations measured in the stationary measuring stations were located in three continental cities – the city of Zagreb (the capital) and cities of Slavonski Brod and Osijek; and two cities at the Adriatic coast – the city of Rijeka and the city of Dubrovnik. The following parameters were analyzed: a daily course of PM2.5 and PM10 concentrations, mean values of daily PM2.5 and PM10 concentrations and average daily PM2.5 and PM10 concentrations, during four seasons in the periods from 2017 to 2019. At most measuring stations, maximum concentrations were recorded during autumn and winter, which can be explained by the intensive use of fossil fuels and traffic. Increases in PM concentrations during the summer months at measuring stations in Rijeka and Dubrovnik may be associated with the intensive arrival of tourists by air during the tourist season, and lower PM concentrations during the winter periods caused by a milder climate consequently resulting in lower fossil fuels consumption and the use of electric energy for heating.

  • Open access
  • 47 Reads
Study of Black Carbon (BC) Mass Concentration Variation at Coastal Region (Surat)
Published: 13 November 2020 by MDPI in The 3rd International Electronic Conference on Atmospheric Sciences session Aerosols

Black Carbon (BC) aerosols mass concentration is study at Surat, Gujarat (INDIA), costal region near the Tapi River at the Gulf of Khambhat. Using Satellite data for solar extinction due to Black Carbon (BC) mass concentration data have been collected from the Giovanni site (http://giovanni.gsfc.nasa.gov/giovanni/) developed by NASA. Results of the data for the 5-year period (January to December 2001-2005) have been discussed here. Annual and Seasonal variations of black carbon (BC) in relation to changes in the regional meteorological conditions. The data collected during January to December 2001-2005 indicated that annual average BC concentration. The mean annual variations of BC aerosols mass concentration seen the maximum in the month of December while minimum in the month of July. The seasonal mean BC mass concentration is lowest observed in monsoon while highest in winter at the study region. Variation of BC trend observed higher in the month December and lower in the month July which is mostly related to the changes in the local boundary layer.

  • Open access
  • 100 Reads
Future Thermal Assessment for the Phenological Development of Potato (Solanum tuberosum L.) in Cuba

Current changes in climate conditions due to global warming affect the phenological behavior of economically important cultivable plant species, with consequences for the food security of many countries, particularly in small vulnerable islands. Thus, the objective of this study was to evaluate the thermal viability of Solanum tuberosum (L.) through the behavior of the Thermal Index of Biological Development (ITDB) of two cultivation areas in Cuba under different climate change scenarios. For the analysis, were elaborated bioclimatic scenarios by calculating the ITDB through a grounded and parameterized stochastic function on the basis of the thermal values established for the phenological development of the species. To do it was used mean temperature values from the period 1980 to 2010 (historical reference period) of the Meteorological Stations: 78320 “Güira de Melena” and 78,346 “Venezuela”, located at the western and central of Cuba respectively. Besides was used modeled data from RCP 2.6 scenarios; 4.5 and 8.5 from the PRECIS-CARIBE Regional Climate Model which used global outputs from the ECHAM5 MCG for the period 2010 to 2100. As result, the scenarios show that the annual average ITDB ranges from 0.7 to 0.8, which indicates that until 2010 there were temporary spaces with favorable thermal conditions for the species, but not for the period from 2010 to 2100 in RCP 4.5 and 8.5. In these scenarios, there is a progressive decrease in the indicator that warns of a marked loss of Viability of S. tuberosum, reduction of the time-space to cultivate this species (particularly the month of April is the most inappropriate for the ripening of the tuber). These results show that Cuba requires the establishment of an adaptation program with adjustments in the sowing and production calendar, the use of short-cycle varieties of less than 120 days, the management of genotypes adaptable to high temperatures, and the application of "Agriculture Climate Smart”, to reduce risks in food safety.

  • Open access
  • 42 Reads
Drought: An External Agri-project Risk Analysis for Thabana Morena Constituency Number 52, Mafeteng, Lesotho

Climate change has proven to increase the odds of worsening drought events around the globe, resulting in adverse effects on society, economy and environment. The current study aimed at characterising drought events in the study area in order to alert responsible government department and all other relevant authorities for proactive response before it is too late. The researcher collected precipitation datasets from NASA data portal alongside the main Thabana Morena road. For quality control, both homogeneity and stationarity test were conducted. Prior to this, outliers were detected and replace back by Expectation Maximum algorithm aided by SPSS. Three computer programmes were used in this study, namely; DMAP, XLSTAT and PAST3. Drought was quantified on two temporal time scales to pick up both agricultural and hydrological drought episodes. Major results indicated most stations having homogenous precipitation datasets and as such only two distant stations (Ha Thakanyane and Ramarothole) were used in further analysis. Ha Thakanyane and Ramarothole depicted constant and statistically increasing severe drought conditions on both temporal scales over 38 years respectively. The situation warrants sustainable off-agricultural interventional measures by the government and all relevant stakeholders to protect environment and human lives that are dependent on rainfed agriculture for livelihood.

  • Open access
  • 41 Reads
Projecting Northern Hemisphere Flow Regime Transitions: The Use of Integrated Enstrophy

Integrated enstrophy (IE) is the square of vorticity integrated over an entire hemisphere at a particular level in the atmosphere. Previous work has shown this quantity is correlated to the positive Lyapunov Exponent for hemispheric flow, and as such is a measure of flow stability or predictability. In this study, IE is calculated at 500-hPa over an area that encompasses 0° to 70° in the Northern Hemisphere. The data sets used were the 500-hPa initial and forecast fields for the Global Ensemble Forecasting System (GEFS) (on a 1o x 1o latitude-longitude grid) provided by the National Oceanic and Atmospheric Administration (NOAA) Weather Prediction Center (WPC) and the National Centers for Environmental Prediction / NOAA reanalyses (on a 2.5o x 2.5o latitude-longitude grid) archived in Boulder, CO. The GEFS forecast fields were provided every 24-h out to 240-h. By examining these forecasts over a year, it was found here that significant changes in IE values are a good predictor of flow regime transition, and several cases were found. We also found that the IE forecasts identified these regime transitions reliably out to about four days, however, the probability of detection and the skill decreased significantly after this time. Additionally, this work demonstrates that the changes in large-scale flow identified by IE can also signal large changes in the local weather and climate conditions.

  • Open access
  • 68 Reads
Diurnal Dynamics of the Reduced Turbulent Kinetic Energy of in the Atmospheric Boundary Layer from Minisodar Measurements

Based on acoustic remote measurements of the diurnal dynamics of three wind velocity components and their standard deviations in the lower 200-meter layer of the atmosphere, the kinetic energy of the atmosphere reduced to unit mass is estimated, with a particular emphasis on the turbulent kinetic energy component. For a 24-h period of continuous minisodar observations, the turbulent energy in the surface layer was very low to altitudes of ~50 m. With increase in altitude from 50 to 100 m, the turbulent kinetic energy quickly increased, and at altitudes exceeding 100 m, its fast growth is observed, with a maximum at altitudes of 150–200 m. Essential influence of time of the day on the results of observations was established. Thus, at night at the same altitudes the kinetic energy density first did not exceed 20 J/kg, and its moderate growth (from 20 to 50 J/kg) was observed with increasing time. In the morning, the maximum energy density of air masses was observed. After sunrise, the turbulent component of the kinetic energy density rapidly decreased. It is essential that the system the Earth surface – the near-ground air layer tends to an equilibrium state. As a consequence, the spread of values of the turbulent energy is reduced. The most significant changes were observed at altitudes in the range 100–200 m. It is essential that at altitudes up to 50–100 m, time of the day had no significant effect, because at these altitudes the turbulent energy was low and remained practically unchanged with time. At any time of the day, the maximum turbulent energy was observed at altitudes in the range 100–200 m that pose the greatest danger to small flying objects.Of special importance are the wind direction and modulus, that is, the magnitude and direction of the vector of the turbulent energy flux density at various altitude . It has been pointed out that the direction of this vector coincides with the direction of the horizontal wind velocity component. The corresponding estimations are presented.

  • Open access
  • 56 Reads
Optical Properties and Direct Radiative Effects of Aerosol Species at Global Scale Based on the Synergistic Use of MERRA-2 Optical Properties and the Forth Radiative Transfer Model
Published: 13 November 2020 by MDPI in The 3rd International Electronic Conference on Atmospheric Sciences session Aerosols

The overarching goal of the current study is to quantify the aerosol induced clear-sky direct radiative effects (DREs) within the Earth-Atmosphere system at global scale and for the 40-year period 1979-2019. To this aim, the MERRA-2 aerosol radiative properties, along with meteorological fields and surface albedo, are utilized as inputs to the FORTH radiative transfer model (RTM). Our preliminary results, representative for the year 2015, reveal strong surface radiative cooling (down to -45 Wm-2) over areas where high aerosol loadings and absorbing particles (i.e., dust and biomass burning) dominate. This reduction of the incoming solar radiation, in the aforementionned regions, is largely attributed to its absorption by the overlying suspended particles resulting in an atmospheric warming reaching up to 40 Wm-2. At the top-of-atmosphere (TOA) negative DREs (planetary cooling) are computed worldwide (down to -20 Wm-2) with few exceptions over bright surfaces (warming up to 5 Wm-2). Finally, the strong variations between the obtained DREs of different aerosol species (dust, sea-salt, sulphate, organic/black carbon) as well as between hemispheres and surface types (i.e., land vs ocean) are also discussed.

  • Open access
  • 38 Reads
Emissions of Reactive Organics from Oil and Gas-Related Combustion Sources

While methane emissions from oil and gas operations have been the focus of many recent studies, less work has been carried out to understand oil and gas-related emissions of non-methane organics. Much of the available information on this topic is decades old, contains few samples, and does not include the full speciation needed to understand the air quality and human health impacts of these important emission sources. We have engaged in several recent projects to better understand the magnitude and speciation of non-methane organic compound emissions from oil and gas sources. This presentation focuses on findings from deployments of 17 portable sample collection stations around Utah’s Uinta Basin. We used these stations to collect hundreds of atmospheric samples in several deployment configurations over two years and analyzed the samples for a suite of 72 volatile organics, including hydrocarbons, alcohols, and carbonyls.

We found that concentrations of reactive organics, including alkenes and aldehydes, were higher in areas dominated by oil development compared to areas dominated by gas development. Ethylene and propylene stood out in particular, with a few samples exhibiting ethylene+propylene concentrations higher than the sum of all alkanes. Overall, alkenes were more than 10% of total organics in oil-dominated areas, compared with just 2% in gas-dominated areas, and aldehydes were significantly higher in oil-dominated areas as well. What is more, light alkenes were responsible for about 40% of the total ozone reactivity of atmospheric organics in the oil-producing Uinta Basin, and carbonyls accounted for 10%.

Most oil wells in the Uinta Basin utilize two-stroke, rich-burning artificial lift engines to bring oil to the surface, while gas wells do not. Combustion processes like those from engines are known to emit alkenes and aldehydes, and rich-burn conditions are associated with incomplete combustion and increased emissions of reactive organics. Recent direct emissions measurements also point to artificial lift engines as the probable source of elevated alkenes and aldehydes in the oil-producing Uinta Basin. These lines of evidence together show that emissions of reactive organics from oilfield engines are likely higher than has previously been assumed.

  • Open access
  • 59 Reads
The causal relationship between agricultural practices, climate change and greenhouse gas recovery

The paper provides an overview of the agricultural economy in terms of agricultural development, especially in the field of application of agricultural techniques depending on climatic zones. Environmental protection and sustainable management of natural resources, prioritizing action behavior in terms of good practice methods in soil treatments, especially vulnerabilities on the types of fertilizers used, are part of the soil-plant-air-water equation. The change of paradigms in agriculture with climate change involves the adaptation of agricultural systems the risks of using fertilizers in soil treatment, the interdependence of plant-soil-water in agricultural practice is also highlighted in the paper. One of the main objectives in the field of agriculture is to maintain a low level of greenhouse gas emissions from the agricultural sector without diminishing the importance of biosphere protection. The role of research and studies has shown an important factor in reducing the carbon footprint per tonne of food produced from organic farming compared to conventional farming, mainly due to the abandonment of the use of chemical fertilizers and pesticides. So on Maslow's motivational scale, looking at the evolution of needs In relation to their satisfaction, we simulated the relative motivational value of the needs determined on the basis of experience. The purpose of the following research is to collect data and information on the most effective management models that will create the premises for agricultural practices applied to the soil by preventing pollution of groundwater and surface water with nitrates. from agricultural sources and by promoting the use of good practices farm. The Common Agricultural Policy (CAP) supports the Nitrates Directive by granting direct assistance and through rural development measures. There is also a growing trend for agro-ecological initiatives for which farmers can receive payments. nutrient management measures, such as the creation of buffer zones, as an element to stimulate environmental protection. During the research we tried to highlight aspects that, in our opinion, are important for the development of the agricultural sector through innovative rural development measures as part of the economy.

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